Immunohistological analysis reveals IgG1-dominant immunophenotype of tubulointerstitial nephritis unassociated with IgG4-related diseases

Toshiki Hyodo; Shigeo Hara; Shunsuke Goto; Hideki Fujii; Shinichi Nishi; Tomoko Horinouchi; Kandai Nozu; Norishige Yoshikawa; Akihiro Yoshimoto; Tomoo Itoh

doi:10.1007/s11255-024-03966-1

Immunohistological analysis reveals IgG1-dominant immunophenotype of tubulointerstitial nephritis unassociated with IgG4-related diseases

Int Urol Nephrol. 2024 Feb 21. doi: 10.1007/s11255-024-03966-1. Online ahead of print.

Authors

Toshiki Hyodo¹, Shigeo Hara^{2

3}, Shunsuke Goto⁴, Hideki Fujii⁴, Shinichi Nishi⁴, Tomoko Horinouchi⁵, Kandai Nozu⁵, Norishige Yoshikawa⁶, Akihiro Yoshimoto⁷, Tomoo Itoh²

Affiliations

¹ Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan. bari1049@med.kobe-u.ac.jp.
² Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
³ Department of Diagnostic Pathology, Kobe City Medical Center General Hospital, Kobe, Japan.
⁴ Division of Nephrology and Kidney Center, Kobe University Graduate School of Medicine, Kobe, Japan.
⁵ Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.
⁶ Clinical Research Center, Takatsuki General Hospital, Takatsuki, Japan.
⁷ Department of Nephrology, Kobe City Medical Center General Hospital, Kobe, Japan.

PMID: 38381285
DOI: 10.1007/s11255-024-03966-1

Abstract

Purpose: Tubulointerstitial nephritis (TIN) has various etiologies, including IgG4-related disease (IgG4-RD), autoimmune diseases, antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), and others. IgG4-positive plasma cell infiltration can occasionally be found in TIN unrelated to IgG4-RD. Therefore, there may be problems with usage of IgG4 immunostaining to differentiate between TIN with and TIN without IgG4-RD. This study aimed to compare the proportion of plasma cells that are positive for each IgG subclass and to clarify the predominant IgG subclass trends and clinical characteristics associated with IgG4-RD and non-IgG4-related interstitial nephritis.

Methods: The study enrolled 44 cases of TIN: 6 of IgG4-RD, 8 of autoimmune disease, 9 of AAV, and 21 of unknown disease group. In addition to clinical characteristics, IgG subclass composition of interstitial plasma cells was evaluated among 4 groups by immunohistochemistry.

Results: IgG1 was the predominant IgG subclass in TIN unrelated to IgG4-RD. In the IgG4-RD group, the IgG subclass rate was high in both IgG1 and IgG4. The rate of average IgG4-positive cells was significantly lower in the autoimmune disease group and unknown disease group compared with the IgG4-RD group.

Conclusion: The present study revealed IgG1-dominant immune profiles of TIN unrelated to IgG4-RD. Further investigation is required to elucidate the clinicopathological differences between IgG1-dominant and IgG4-dominant groups in IgG4-RD.

Keywords: IgG subclass; IgG1; IgG4; Plasma cells; Tubulointerstitial nephritis.